This invention relates to races wherein two or more contestants travel over a course to a finish line and the contestant who crosses the finish line first wins the race. More specifically, the invention is directed to a method of, and the construction of apparatus for, providing an unambiguous view of the crossing of the finish line of a race course by the winner.
Various ways of determining the winner of a race are known in the art. U.S. Pat. No. 3,829,869, issued to Balko et al. in 1974, is of historical interest to the extent that it describes a high-speed mechanical camera which records the crossing of a finish line on film. The image is displayed as viewed along a direction within the plane of the finish line. U.S. Pat. No. 4,274,076 to Hermanns et al. provides for the contestants in a race to wear transmitters which emit a signal that is sensed by receivers at the finish line of a race course. U.S. Pat. No. 4,523,204 to Bovay teaches the use of film or magnetic media to record both the start and finish of a race in a single image, e.g., by having a first flash fired at the starting bell and another flash fired as the finish line is crossed.
U.S. Pat. No. 5,793,900 to Nourbakhsh et al. tells how to employ three cameras focused at different distances from objects in a common scene to create a three dimensional xe2x80x9cdepth mapxe2x80x9d of the scene. Proposed uses include motion detection and automobile speed measurement. U.S. Pat. No. 3,883,684 to Ikegami et al. discloses a real-time system for periodically photographing a moving object and printing the corresponding images on a medium which is moved so that the images are displaced on the medium as a function of the velocity of the object. U.S. Pat. No. 5,889,878 to Togashi improves upon a method of detecting the position of a moving object wherein a fixed reference line and the moving object are isolated from the background on which they are photographed and the position of the moving object can then be determined by repeatedly calculating its distance from the reference line.
None of the above proposed solutions provides an observer with a view of the contestants in a race which enables him or her to simply and unambiguously see a head-on unobstructed view of the winner of a race crossing the finish line, even when other contestants finish very close to the winner.
The aforementioned problems of the prior art are overcome by the instant invention which provides for giving viewers of a sports event, e.g., a race, the ability to see who won at the moment the winner crosses the finish line. A camera defines a plane by assigning a depth to the finish line and recording it as an xe2x80x9calphaxe2x80x9d or xe2x80x9cZ depthxe2x80x9d channel. Any object moving from beyond that depth and to a position forward of it will appear to be breaking through the plane.
Video cameras are known which can provide an image of what is within the angle of view of the camera lens only at a fixed distance from the camera. That is, everything closer to, or farther from the plane of focus is eliminated from the view. Several such pictures at closely spaced distances from the camera can be superimposed to provide a view of a three dimensional object without any background. The invention involves the adaptation of this type of camera to the aforesaid application, i.e., viewing a racer in the plane of the finish line of a race course as he crosses the line. A clock may be provided to add to the display a reading of the instant time at which the finish line is crossed.
On a video monitor, a viewer sees nothing but a blank screen until something or someone emerges through the finish line plane. With a camera scanning the finish line at typical speeds of up to 1000 frames per second, one can see a figure emerging through the plane and determine without doubt who is the actual winner of the race.
It is therefore an object of the invention to provide a viewer of a race with an unambiguous real time image of the winner of the race as he or she crosses the finish line.
Another object of the invention is to provide a head-on view of the winner breaking through a vertical plane intersecting the finish line.
Still another object of the invention is to provide a head-on view of only the portions of the body of the winner which have passed the finish line.
A further object of the invention is to provide head-on views of the portions of the body of the winner which have passed the finish line in rapid sequence thereby enabling the crossing of the finish line to be seen in real time animation.
Still a further object of the invention is to provide accurate head-on views of the portions of the body of the winner which have passed the finish line irrespective of the distances of the body portions from the camera""s viewing axis.